That wasn't really my point but rather that social ownership of the means of production is a defining characteristic of socialism (as it was conceived in opposition to capitalism). Maybe there is a voluntary way to it but I don't think that has happened anywhere on a large scale so far.

These days there is a tendency to use socialism and practical present-day social democracy rather interchangeably, but I think that is problematic (and the latter doesn't really aim for socialism anymore, I'd say).